PSY402 Theories of Learning

1. PSY402Theories of Learning Chapter 4 (Cont.) Schedules of Reinforcement

2. Schedules of Reinforcement • When and how often reinforcement occurs affects learning. • Two kinds of schedules: • When = interval schedules • How often = ratio schedules • Each kind of schedule can be either fixed or variable.

3. Interval Schedules • Fixed Interval (FI) – reinforcement is available regularly after a certain amount of time goes by. • The behavior must still be performed. • Scallop effect. • Variable Interval (VI) – the time that must go by before reward varies. • Described as an average time

4. Ratio Schedules • Fixed Ratio (FR) – a specified number of behaviors must be completed before reward is given. • Post-reinforcement pause • Variable Ratio (VR) – the number of behaviors needed to obtain reward is different each time. • Described by an average

5. Differential Reinforcement • Reward is contingent on performing the behavior within a specified period of time. • Example: due dates for class assignments • For interval schedules, reward is also contingent on behavior but the opportunity still exists after each interval ends.

6. DRH Schedules • Differential reinforcement can be made contingent on a high rate of responding. • May create a vicious circle: • Danger that the animal will give up if the high rate cannot be maintained. • If responding decreases, no reward will be obtained. • Without reward, the behavior decreases.

7. DRL Schedules • Reinforcement is contingent on a low rate of responding. • Animal is reinforced for withholding its behavior – not for showing it. • If a period goes by without a response then the reward is given.